Carrera Crossfuse (Active Line Plus) struggling with hills

[Rolling Sly Stone]

Having exchanged my Carrera Crossfire (Suntour HEC motor) for a Crossfuse (Bosch Active Line Plus motor), I was disappointed to find that it has nowhere near as much ‘pull’ up hills. My missus still has a Crossfire so I have done direct comparisons. The Crossfuse seriously lacks power compared to the Crossfire. Don’t get me wrong, it’s a nicer ride with the central mounted motor and it also rolls much nicer on flats and downhill but I am somewhat disappointed with its pulling power.

Has anyone else found it lacks power? I’m wondering whether it could possibly be faulty or whether Bosch may have released a software update that would improve this?

 

[Wicky]

Suntour is a hub motor with a bit more torque for hill climbing and different sensor system and delivery compared to crank driven Bosch which is more akin to normal cycling with use of gears req.

Carrera Crossfire E 2020

Carrera is Halfords own-brand budget range of regular and electrically-assisted e-bikes. Their latest 2020 model year, hybrid-style electric offering is the Crossfire E which uses a rear hub motor from far-eastern component manufacturer SR Suntour (of budget suspension fork fame). Buy the...

ebiketips.road.cc

The first thing to say is the more powerful motor on the Crossfire was immediately noticeable when compared to my previous experience of the HESC system on the Vengeance. It was not only quick out of the blocks but it maintained its speed up hills. On my regular mile long tarmac hill climb it also returned a time that was in the middle of the leading peloton of previous test bikes that have included some fine quality mid-drives.

All Ebiketips’ previous reviews of the HESC systems loved the smooth power delivery, delivered by their own unique torque sensing system housed in the large plastic disc affair attached to the chainwheel, and this one is no exception. The system senses the pressure you put on the pedals rather than the movement of the cranks or chainwheel as inferior speed sensing systems do. The result is more immediate power delivery that is much more in tune with you pedalling action.

The power feels smoother and more in proportion to the effort you are putting into pedalling (especially important for hill climbing and close control of the bike in busy traffic)

 

[Amoto65]

I have owned both these models and found the Crossfuse the better of the two, The reliability of the Bosch engine in the Crossfuse is far superior, the ride feels more natural on the Crossfuse. I have not found any problems climbing hills and I live in the Peak District.

 

[Rolling Sly Stone]

Thanks for the responses. @Amoto65 I agree the Bosch is clearly the superior ‘quality’ motor but did you find the Crossfire considerably better on inclines? My Mrs, who is a rubbish cyclist and usually doesn’t go anywhere near as fast as me, simply cruises past me up hills. Surely the Bosch motor is capable of more? Is there any way of finding out if it’s ever been ‘tweaked’ in a software update? I bought it around 2 years ago.

 

[sjpt]

How hard are you pushing? Wicky mentioned the sensor. On top setting the Suntour will deliver all it can as long as you are pedalling. The Bosch even on turbo will only deliver 3 times what you put in (up to its maximum). You need to be in low gear and spinning at a decent cadence as well to get the most out of the Bosch.

 

[Amoto65]

Thanks for the responses. @Amoto65 I agree the Bosch is clearly the superior ‘quality’ motor but did you find the Crossfire considerably better on inclines? My Mrs, who is a rubbish cyclist and usually doesn’t go anywhere near as fast as me, simply cruises past me up hills. Surely the Bosch motor is capable of more? Is there any way of finding out if it’s ever been ‘tweaked’ in a software update? I bought it around 2 years ago.

I think the riding style is totally different between the 2 bikes as mentioned previously you have to be in the right gear and at the right cadence with the Bosch where as the other it pushes you along with minimal effort. I have found the tour mode at a decent cadence usually gets me up 10/12 % hills.

 

[Rolling Sly Stone]

How hard are you pushing? Wicky mentioned the sensor. On top setting the Suntour will deliver all it can as long as you are pedalling. The Bosch even on turbo will only deliver 3 times what you put in (up to its maximum). You need to be in low gear and spinning at a decent cadence as well to get the most out of the Bosch.

I’m pushing quite hard and yes, it definitely does have to be in a low gear. I’ve not heard about the delivering 3 x what you put in before? If that’s the case, that only makes me lean even more towards the possibility of my motor underperforming.

 

[Bonzo Banana]

I have owned both these models and found the Crossfuse the better of the two, The reliability of the Bosch engine in the Crossfuse is far superior, the ride feels more natural on the Crossfuse. I have not found any problems climbing hills and I live in the Peak District.

There has been lots of problems with Bosch motors and some pretty staggering repair bills for those who had problems and had to pay however compared to the Suntour system which has had the crankset/torque sensor area issues it's hard to say which is worse but certainly as a general rule motor hubs are much simpler and more reliable. Maybe problems with the Suntours happen earlier but that is good in a way as will be in warranty but some of the Bosch's seem to have a lot of plastic gearing and fairly short life internal components that simply wear out and fail fairly quickly. They also restrict the supply of spare parts to dealers only at least for some parts which can add to costs. I realise Bosch has tried to address this in the latest version but whether they have done this successfully is another matter but I believe they have improved and simplified the design in some of the motors and improved the seals against water ingress. Suntour problems seem to be more about minor part design issues which you can often work around and fix yourself where as Bosch problems tend to be massive motor issues that are expensive and time consuming to sort.

 

[Fishy]

I’m pushing quite hard and yes, it definitely does have to be in a low gear. I’ve not heard about the delivering 3 x what you put in before? If that’s the case, that only makes me lean even more towards the possibility of my motor underperforming.

What assistance level are you using?

 

[Bonzo Banana]

Having exchanged my Carrera Crossfire (Suntour HEC motor) for a Crossfuse (Bosch Active Line Plus motor), I was disappointed to find that it has nowhere near as much ‘pull’ up hills. My missus still has a Crossfire so I have done direct comparisons. The Crossfuse seriously lacks power compared to the Crossfire. Don’t get me wrong, it’s a nicer ride with the central mounted motor and it also rolls much nicer on flats and downhill but I am somewhat disappointed with its pulling power.

Has anyone else found it lacks power? I’m wondering whether it could possibly be faulty or whether Bosch may have released a software update that would improve this?

That sounds right to me, the Suntour is 60Nm torque, the Bosch Active Line Plus is 50Nm plus the drive ratio is 42/34 in the easiest gear and with the loss of power through the chain of about 4% that should mean it is about 38Nm torque on your bike so quite a deficit of power compared to the Suntour. So I would say perfectly normal and to be expected. Remember the motor's in mid-drive motors are quite small, the motor, drive components and circuitry have to fit into quite a small space. Any chance the bike will take a wider cassette at the rear, if it could fit a 11-42T cassette you could get up to something like 48Nm because you would have a 1:1 ratio in the easiest gear.

 

[Wicky]

This is why test riding a variety of models / types is recommended before committing cash.

I took the opportunity to try out different bikes out at the Redbridge Cycling Centre demo day - I was mainly interested in torquey hill climbing ability and I was sold on the 48V KTM hub drive which outperformed every other bike confirming write ups about it. Still performing faultlessly after 6 years, though it was discontinued a year or so ago in favour of more fashionable crank drives.

 

[Woosh]

the output of a CD motor is proportional to the cadence.
The problem is this: most riders can't keep their cadence at 100+ RPM to get the most out of the motor when climbing hills.
If you like CD kits, have steep hills and are not very fit, choose the 48V TSDZ2T with throttle.
It will give you the best of both worlds.

 

[Amoto65]

the Bosch Active Line Plus is 50Nm plus the drive ratio is 42/34 in the easiest gear and with the loss of power through the chain of about 4% that should mean it is about 38Nm torque on your bike

Am I missing something here? how does a loss of 4% of 50Nm equate to 38Nm?

 

[Bonzo Banana]

Am I missing something here? how does a loss of 4% of 50Nm equate to 38Nm?

Am I missing something here? how does a loss of 4% of 50Nm equate to 38Nm?

The 4% is taken off after the drive ratio calculation. 34/42 *50Nm minus 4%

It was only a rough calculation in my head, basically it looked like 0.75x50 plus a bit.

I think the torque is measured at the crank so if you had a 42T front chainring and 42T rear cog you would have the full 50Nm torque because of the 1:1 ratio minus 4% power loss through the chain so 48Nm. However the front chainring turns the rear wheel 42/34 ratio i.e. for every 3 turns of the chainring the rear 34T cog/wheel turns 4 times approx so torque is reduced.

 

[Fishy]

the output of a CD motor is proportional to the cadence.
The problem is this: most riders can't keep their cadence at 100+ RPM to get the most out of the motor when climbing hills.
If you like CD kits, have steep hills and are not very fit, choose the 48V TSDZ2T with throttle.
It will give you the best of both worlds.

That's not my experience, I have a cx motor, (admittedly more torque), but my cadence never reaches 100+, I average 60-65, and glide up hills very easily in turbo mode and low gear.
It literally feels like just spinning the cranks with hardly any effort on my part.

 

[Darren Hayward]

Its rubbish science. Torque is in part a function of gearing, in lower gears there is more torgue. A mid drive motor in bottom gear should give more than the headline 50Nm.
I think Woosh is wrong too. The ALP is only capable of just over 100rpm. Anyone who rides one at 100+ rpm has no support because they are outpacing the motor. Since I lowered my gearing I've been getting the change up symbol on the display as often as the change down (on my 42/32 ALP Intuvio). I can max out support in turbo well short of 100 cadence

Lets talk displays. Does the Crossfuse have an Intuvio or Purion? The Intuvio should show the level of support and in Turbo with it maxed out you should have no trouble going up hills.

I plus my bike weigh 143Kg and I've got dodgy knees. I can get up 12% hills without using my new lower gearing and 16% with bottom gear.


Darren

 

[Amoto65]

Does the Crossfuse have an Intuvio or Purion?

Crossfuse has the purion display.

 

[Woosh]

Torque is in part a function of gearing, in lower gears there is more torgue. A mid drive motor in bottom gear should give more than the headline 50Nm.

Torque is measured at the cranks for crank drive motors, and at the wheels for hub motors.
When a crank drive motor turns the rear wheel, what is conserved is the power of the motor.
The relationship between power and torque is: power (in Watts like 250W) = torque (in Newton Meter NM) * rotational speed (in radian per second, rad/s).
the torque is inversely proportional to the rotational speed, if your rear cog has fewer teeth, your wheel spins faster but with less torque. If you have a hill to climb, you can't climb it in the wrong gear because the motor will give you too little torque.
All torque measurements for crank drive e-bike motors are for a ratio 1:1 - same number of teeth on the rear cog as on the chainring.
If you want to compare how strong a hub motor is against a crank motor, you need to specify a context, such as speed, gear ratio and usually the gradient and the combined weight of rider + bike.
I use the motor emulator at ebikes.ca for that.

Futility of Motor Power Ratings

"There's no such thing as a rated watt!" Read here for why we don't advertise a simple power rating for the motors we sell. Also, have a look at our Youtube video where Justin talks about the power to propel bicycles in <a href="https://www.youtube.com/watch?v=ALde6zhLPs0">"School of Watts"</a>.

www.ebikes.ca

Most of the time, you find hub motors at 40NM-60NM, crank motors at 60NM-100NM.
That does not mean that hub motors are less strong than crank motors because most of the time, people select a smaller cog than their chainring, but because you can select the best gear for the gradient, you can use your crank drive motor more efficiently than your hub motor when the going gets real tough.
Don't forget that you have to pedal much harder with a bike fitted with torque sensor, if you need X, you have to input at least 25% of X.
A lot of riders can't cope with hills with a torque sensor bikes because they can't maintain a high enough input.

 

[Bonzo Banana]

Its rubbish science. Torque is in part a function of gearing, in lower gears there is more torgue. A mid drive motor in bottom gear should give more than the headline 50Nm.
I think Woosh is wrong too. The ALP is only capable of just over 100rpm. Anyone who rides one at 100+ rpm has no support because they are outpacing the motor. Since I lowered my gearing I've been getting the change up symbol on the display as often as the change down (on my 42/32 ALP Intuvio). I can max out support in turbo well short of 100 cadence

Lets talk displays. Does the Crossfuse have an Intuvio or Purion? The Intuvio should show the level of support and in Turbo with it maxed out you should have no trouble going up hills.

I plus my bike weigh 143Kg and I've got dodgy knees. I can get up 12% hills without using my new lower gearing and 16% with bottom gear.


Darren

Surely the torque figure they give will be the maximum they can get away with claiming and its its at the crank the only way they could increase the torque is if the rear cog is larger than the crankset chainring, i.e. 50T rear cog and 42T chainring which would increase that torque figure.

I think one of the benefits of the mid-drive motors is they scale the motor support better to make them more efficient. I.e. If you have 4 power levels over 9 gears you have 36 basic power levels where as a hub drive with 4 power levels has 4 basic power levels before you factor in increase or decrease in power related to cadence and torque that the controller controls. That is the advantage more efficient use of power could mean longer range, they are better at offering reduced support on the flats. A mid-drive motor is always going to be weaker than a hub drive with a equal or higher torque figure I would of thought in the real world because in most applications at best it can only achieve about 75% or less of their claimed torque figures and in many cases far worse. As I said previously mid-drive motors are quite small motors and absolutely tiny compared to direct drive motor hubs with geared motor hubs in the middle.

I'm a heavy rider so use a direct drive motor hub but for me trying to be fair my preference is always a geared hub motor they just seem the sweet spot for reliability and functionality especially where paired with a torque sensor unless you want a real e-mountain bike and you really can't beat a high power mid-drive unit.

 

[Woosh]

I think one of the benefits of the mid-drive motors is they scale the motor support better to make them more efficient. I.e. If you have 4 power levels over 9 gears you have 36 basic power levels where as a hub drive with 4 power levels has 4 basic power levels before you factor in increase or decrease in power related to cadence and torque that the controller controls.

the word 'scale' as in 'they scale the motor support' is a good choice of word.
however, 4 (or more often 5) basic power levels are perfectly good for what we need because within each power level, you can control theoretically between 0% to 100% by varying your input.
There is no real need for more levels. What you want is the maximum power the motor can give is high enough for your toughest hill.